Poster Printing File Setup Guide: Resolution, Bleed, Colour and PDF Export

Overview

A print-ready file should match the finished poster size, contain enough image information for that size, and leave the printer a clean area to trim. It should also preserve the intended colours, typography and layout when opened on another computer or processed by a print workflow.

Before designing, confirm the finished dimensions. Common UK poster sizes include A3, A2, A1 and A0, but custom size poster printing may require non-standard dimensions. Our UK poster size guide explains how these formats relate to one another.

For most posters, vector artwork is ideal for logos, text, icons and simple illustrations because it remains sharp at different sizes. Photos and textured artwork are raster images, so their effective resolution matters. A file can look sharp on screen but still print softly if the image contains too few pixels for the intended output.

Resolution: a practical guide

For close-viewed posters and art prints, 300 ppi at the final printed size is a useful target where the original image supports it. Large posters viewed from farther away can sometimes work at a lower effective resolution, but do not enlarge a small image without checking the result at 100% on screen.

• A2: approximately 4961 × 7016 pixels at 300 ppi.
• A1: approximately 7016 × 9933 pixels at 300 ppi.
• A0: approximately 9933 × 14043 pixels at 300 ppi.

These figures describe the artwork area before any bleed is added. They are working references rather than a substitute for the printer’s specification. For a wall poster viewed at a distance, a lower effective resolution may be acceptable; for a detailed photo poster or art print reproduction, preserve as much genuine image detail as possible.

Checklist by scenario

Photo poster printing

• Set the document to the final poster dimensions and orientation.
• Use the highest-quality original image available rather than a downloaded preview or screenshot.
• Check the image at 100% view for softness, compression blocks, noise and unwanted cropping.
• Keep important faces, horizons and subjects away from the trim edge.
• Decide whether the image should be printed with a matte or gloss finish; the surface can affect perceived contrast and reflections. See the guide to poster and art print paper finishes.

Art prints and reproduction artwork

• Work from a properly scanned or photographed original, with even lighting and no visible glare.
• Keep a master file separate from the print export so colour and cropping can be adjusted later.
• Check fine lines, paper texture and subtle highlights at the intended print size.
• Confirm whether the chosen print process and paper are suitable for the level of detail required.
• Review the advice in How to prepare artwork for poster and art print reproduction before exporting.

Event and exhibition posters

• Set up the final size before placing dates, times, addresses or QR codes.
• Use a clear hierarchy: event name first, followed by essential information and supporting details.
• Keep text and logos inside the safe margin, especially if the poster will be trimmed.
• Test every QR code from the exported PDF or a printed proof, not only from the design file.
• Check that the selected size suits the display location. For planning help, see the event poster printing checklist and exhibition poster guidance.

Business and promotional posters

• Use approved brand colours, logos and typefaces consistently.
• Make the main offer readable at the expected viewing distance.
• Keep contact details, prices and product names accurate in the final proof.
• Check that dark backgrounds do not make small text difficult to read.
• Export one final version with a clear filename, such as spring-sale-A2-final-print.pdf.

What to double-check before PDF export

Bleed, trim and safe margins

Bleed is extra artwork that extends beyond the finished edge, allowing for small movement during trimming. A common working approach is to add 3 mm of bleed on each side, but always follow the printer’s specification. If the finished size is A2, the document with 3 mm bleed on all sides would be 426 × 600 mm rather than 420 × 594 mm.

Extend backgrounds, photographs and colour blocks into the bleed. Do not place essential text, logos or faces there. Keep these elements inside a safe margin; a margin of at least 5 mm is a sensible starting point, with more space often preferable for large-format displays or designs with a strong border.

Colour and black

RGB is commonly used by screens, while CMYK is associated with many print workflows. The correct choice depends on the equipment and workflow being used. If a printer requests CMYK, convert using an appropriate colour profile rather than relying on an unplanned conversion at the end. Some print workflows accept RGB files and manage conversion themselves, so check the supplied artwork requirements before changing colour mode.

Very dark areas can lose detail if they are made from excessive ink coverage or an unsuitable black build. For small black text, a simple black may produce cleaner type; for large solid backgrounds, the printer may recommend a different build. If colour accuracy is important for an art print, brand identity or photographic image, request guidance before finalising the file.

Fonts, transparency and export settings

• Embed fonts in the PDF or convert final text to outlines if your workflow requires it. Keep an editable version with live text for future changes.
• Check transparency, drop shadows, blending modes and overprinting after export.
• Use a print-quality PDF preset, retain the document’s intended dimensions, include bleed when requested and add trim marks only if required.
• Open the exported PDF in a separate viewer and inspect every page before sending it.
• Do not rely on a phone preview to judge small text, fine detail or colour.

For large format printing, also confirm whether the file should be supplied at full scale or at a proportional scale such as 50%. Never assume; a scale mismatch can affect both dimensions and resolution.

Common mistakes

1. Designing at the wrong size: stretching an A4 design to A1 can reduce image quality and make text proportions feel unsuitable.
2. Adding bleed after the layout is finished: this can force important content too close to the edge. Set the document up correctly at the start.
3. Using low-resolution images: a web image may be perfectly usable on screen but too small for a detailed photo poster.
4. Ignoring the crop: automated fitting can remove edges or change the composition. Specify whether the design should be cropped, fitted with a border or printed at its exact ratio.
5. Forgetting linked files: packaged design files may lose images or fonts when moved between computers. A PDF usually avoids this issue, provided it has been exported correctly.
6. Checking only the source file: errors often appear during export. Review the final PDF, including page size, bleed, spelling, colour, QR codes and image sharpness.

A reliable final check is to print a small section at 100% on an ordinary printer. This will not reproduce the final colour or paper, but it can reveal tiny text, awkward line breaks and unexpected softness.

When to revisit this checklist

Save this checklist with your working files and revisit it whenever the finished size, artwork, software or print specification changes. It is especially useful before seasonal campaigns, event deadlines, gallery submissions, shop promotions and repeat orders made from an older design.

Before placing an order, complete this short preflight:

• Finished size and orientation confirmed.
• Resolution checked at the final output size.
• Bleed and safe margins applied according to the specification.
• Images, colours, spelling and QR codes reviewed.
• Fonts embedded or outlined as required.
• PDF opened and checked after export.
• Filename identifies the correct size and final version.
• Paper, finish and display requirements considered.

If you are preparing artwork for a framed print, gallery wall or custom display, confirm the visible area after mounting as well as the paper size. For posters used in shops, venues or exhibitions, also check the viewing distance and installation method. Taking these final steps before ordering helps prevent avoidable cropping, soft images and layout surprises.